He was found drugged and disorientated in a snowdrift in Norway in December, claiming to remember nothing of his past but sporting cuts, bruises and other signs of a kidnapping. But despite DNA analysis proving that the mystery man is Czech, he says he fears returning home until the events leading to his discovery are revealed.

While the age, nationality and identity of the man known until now as “John Smith” were confirmed on Friday, how the 36-year-old Czech ended up unconscious near an Oslo petrol station on 14 December remains unclear. Police found him ill-dressed for the freezing weather and with multiple injuries. He spoke English with a Slavic accent and could also converse in Czech, Slovak, Polish and Russian, but could reveal little else about his identity and had no idea how he ended up in Norway.

Despite appeals to Interpol, Norwegian police failed to make a breakthrough and published his photograph on Tuesday in the hope someone would recognise him. It was only a few days before a couple in the Czech Republic came forward and said he was their son, a development that “John Smith” told Norway’s TV2 broadcaster was “the best thing that could have happened”.

On Friday, Czech police said DNA tests had confirmed that he was indeed the couple’s son, but this was only part of the puzzle. “John Smith” had cuts to his wrists and ankles, indicating that he had been tied up. As well as having drugs in his system when he was found, he was also dehydrated, suggesting he may have been held without food and water.

Norwegian media reported that he had been advised not to reveal his real name, as investigations were ongoing. Police in Norway said that knowing his true identity would help them chase up leads, and in the meantime “John Smith” is staying put. He has invited his parents – whom he still does not recognise – to come to Oslo for a reunion. “I’m looking forward to speaking with them and finding out about my past,” he told Norway’s Dagbladet newspaper.

But he said he had no intention of returning home, given that his unknown assailants would probably have seen media coverage of his discovery and identification. “I fear the criminals who exposed me to this will be there waiting for me,” he added. “I will never return to the Czech Republic.”